Background-Penetration of fractional flow reserve (FFR) in clinical practice varies extensively, and the applicability of results from randomized trials is understudied. We describe the extent to which the information gained from routine FFR affects patient management strategy and clinical outcome. Methods and Results-Nonselected patients undergoing coronary angiography, in which at least 1 lesion was interrogated by FFR, were prospectively enrolled in a multicenter registry. FFR-driven change in management strategy (medical therapy, revascularization, or additional stress imaging) was assessed per-lesion and per-patient, and the agreement between final and initial strategies was recorded. Cardiovascular death, myocardial infarction, or unplanned revascularization (MACE) at 1 year was recorded. A total of 1293 lesions were evaluated in 918 patients (mean FFR, 0.81±0.1). Management plan changed in 406 patients (44.2%) and 584 lesions (45.2%). One-year MACE was 6.9%; patients in whom all lesions were deferred had a lower MACE rate (5.3%) than those with at least 1 lesion revascularized (7.3%) or left untreated despite FFR≤0.80 (13.6%; log-rank P=0.014). At the lesion level, deferral of those with an FFR≤0.80 was associated with a 3.1-fold increase in the hazard of cardiovascular death/myocardial infarction/target lesion revascularization (P=0.012). Independent predictors of target lesion revascularization in the deferred lesions were proximal location of the lesion, B2/C type and FFR. Conclusions-Routine FFR assessment of coronary lesions safely changes management strategy in almost half of the cases. Also, it accurately identifies patients and lesions with a low likelihood of events, in which revascularization can be safely deferred, as opposed to those at high risk when ischemic lesions are left untreated, thus confirming results from randomized trials. Clinical Trial Registration-URL: http://www.clinicaltrials.gov. Unique identifier: NCT01835808. Results from the FAME 2 (Fractional Flow Reserve Versus Angiography for Multivessel Evaluation 2) study suggested that deferring the revascularization of epicardial stenosis with an FFR≤0.80 was associated with an 11.4% absolute increase in the risk of major cardiovascular events at 24 months (8.1% in revascularized patients versus 19.5% in medically treated), an hazard that was mainly driven by urgent revascularization. 4In spite of the overwhelming evidence of its potential clinical and economic benefits 5 and strong guideline recommendation, 6 the adoption of FFR in the real-world is perceived to vary significantly. Reasons for this disparity are several, but most operators still do rely the most on angiographic eyeballing to decide on the functional significance of coronary lesions and the need for revascularization. 7The Portuguese Study on the Evaluation of FFR-Guided Treatment of Coronary Disease (POST-IT) was a prospective registry designed to describe the patterns of the use of FFR in an unselected real-world population, to assess its impact on clinical decis...

IMPORTANCE Approximately one-third of patients considered for coronary revascularization have diabetes, which is a major determinant of clinical outcomes, often influencing the choice of the revascularization strategy. The usefulness of fractional flow reserve (FFR) to guide treatment in this population is understudied and has been questioned. OBJECTIVE To evaluate the usefulness and rate of major adverse cardiovascular events (MACE) of integrating FFR in management decisions for patients with diabetes who undergo coronary angiography. DESIGN, SETTING, AND PARTICIPANTS This cross-sectional study used data from the PRIME-FFR study derived from the merger of the POST-IT study (Portuguese Study on the Evaluation of FFR-Guided Treatment of Coronary Disease [March 2012-November 2013]) and R3F study (French Study of FFR Integrated Multicenter Registries Implementation of FFR in Routine Practice [October 2008-June 2010]), 2 prospective multicenter registries that shared a common design. A population of all-comers for whom angiography disclosed ambiguous lesions was analyzed for rates, patterns, and outcomes associated with management reclassification, including revascularization deferral, in patients with vs without diabetes. Data analysis was performed from June to August 2018. MAIN OUTCOMES AND MEASURES Death from any cause, myocardial infarction, or unplanned revascularization (MACE) at 1 year. RESULTS Among 1983 patients (1503 [77%] male; mean [SD] age, 65 [10] years), 701 had diabetes, and FFR was performed for 1.4 lesions per patient (58.2% of lesions in the left anterior descending artery; mean [SD] stenosis, 56% [11%]; mean [SD] FFR, 0.81 [0.01]). Reclassification by FFR was high and similar in patients with and without diabetes (41.2% vs 37.5%, P = .13), but reclassification from medical treatment to revascularization was more frequent in the former (142 of 342 [41.5%] vs 230 of 730 [31.5%], P = .001). There was no statistical difference between the 1-year rates of MACE in reclassified (9.7%) and nonreclassified patients (12.0%) (P = .37). Among patients with diabetes, FFR-based deferral identified patients with a lower risk of MACE at 12 months (25 of 296 [8.4%]) compared with those undergoing revascularization (47 of 257 [13.1%]) (P = .04), and the rate was of the same magnitude of the observed rate among deferred patients without diabetes (7.9%, P = .87). Status of insulin treatment had no association with outcomes. Patients (6.6% of the population) in whom FFR was disregarded had the highest MACE rates regardless of diabetes status. CONCLUSIONS AND RELEVANCE Routine integration of FFR for the management of coronary artery disease in patients with diabetes may be associated with a high rate of treatment reclassification. Management strategies guided by FFR, including revascularization deferral, may be useful for patients with diabetes.

Background— Fractional flow reserve (FFR) is not firmly established as a guide to treatment in patients with acute coronary syndromes (ACS). Primary goals were to evaluate the impact of integrating FFR on management decisions and on clinical outcome of patients with ACS undergoing coronary angiography, as compared with patients with stable coronary artery disease. Methods and Results— R3F (French FFR Registry) and POST-IT (Portuguese Study on the Evaluation of FFR-Guided Treatment of Coronary Disease), sharing a common design, were pooled as PRIME-FFR (Insights From the POST-IT and R3F Integrated Multicenter Registries - Implementation of FFR in Routine Practice). Investigators prospectively defined management strategy based on angiography before performing FFR. Final decision after FFR and 1-year clinical outcome were recorded. From 1983 patients, in whom FFR was prospectively used to guide treatment, 533 sustained ACS (excluding acute ST-segment–elevation myocardial infarction). In ACS, FFR was performed in 1.4 lesions per patient, mostly in left anterior descending (58%), with a mean percent stenosis of 58±12% and a mean FFR of 0.82±0.09. In patients with ACS, reclassification by FFR was high and similar to those with non-ACS (38% versus 39%; P =NS). The pattern of reclassification was different, however, with less patients with ACS reclassified from revascularization to medical treatment compared with those with non-ACS ( P =0.01). In ACS, 1-year outcome of patients reclassified based on FFR (FFR against angiography) was as good as that of nonreclassified patients (FFR concordant with angiography), with no difference in major cardiovascular event (8.0% versus 11.6%; P =0.20) or symptoms (92.3% versus 94.8% angina free; P =0.25). Moreover, FFR-based deferral to medical treatment was as safe in patients with ACS as in patients with non-ACS (major cardiovascular event, 8.0% versus 8.5%; P =0.83; revascularization, 3.8% versus 5.9%; P =0.24; and freedom from angina, 93.6% versus 90.2%; P =0.35). These findings were confirmed in ACS explored at the culprit lesion. In patients (6%) in whom the information derived from FFR was disregarded, a dire outcome was observed. Conclusions— Routine integration of FFR into the decision-making process of ACS patients with obstructive coronary artery disease is associated with a high reclassification rate of treatment (38%). A management strategy guided by FFR, divergent from that suggested by angiography, including revascularization deferral, is safe in ACS.